JUAN MARTIN DEL POTRO is back in the US Open final — but his joy was tinged with sadness.
A brilliant first set between him and Rafa Nadal had set the stall for what threatened to be a semi-final classic.
Here were two ultimate tennis court warriors thrillingly going toe-to-toe.
Yet both players have suffered with terrible injuries over the years — Delpo almost quit with a succession of wrist problems after winning his maiden, and only, major here back in 2009.
And while his rejuvenated body held firm, it was Nadal’s knees which began to feel the strain once more.
The pain appeared to begin in the second set and didn’t stop. It was the third time he has retired in 283 Grand Slam matches, but two have come in the last year.
Del Potro, 29, was playing too well, hitting the ball too hard, moving him around too much.
With the score at 7-6 6-2 enough was enough for devastated the world no 1 who embraced the South American at the net.
They both know what it’s like. The feeling of utter disappointment coursing through their veins.
Nadal, although he didn’t fully admit it afterwards, wasn’t helped by playing three tough, long, lung-busting matches in the build up to this meeting with the world No3.
The 32-year-old, 17-time slam-winning legend had already spent over 17 hours on court — the longest time spent by anyone — and was pushed to five sets by Dominic Thiem in the quarter-finals.
A gutted Nadal said: "I have had issues during tournament, it got better but at 2-2 in the first set that I started to feel something in my knee.
"After that I was trying to get through and improve but it wasn’t to be.
"I waited for as long as possible but it was very difficult for me to get to the finish.
"You have to take a decision and it was so difficult for me. At the end, it wasn’t a tennis match.
"I hate to retire but to stay another set would have been too much.
This wasn’t how Del Potro wanted to return to the Flushing Meadows final.
He said: "It’s the not best way to win a match, I love to play against him, he is a such a fighter and I don’t like to see him suffering. I am sad for him.
"Anyways the key was the first set, we both played good tennis, it was tough. I did well in the tiebreak and I am so happy to be in the final once again.
"It means a lot to me, I didn’t expect to get into another slam final, especially here at my favourite tournament.
"My best memories are at Flushing Meadows. In the final when I beat Rafa and then Roger I was a kid then, but now I am much older."
The last time these two fearsome strikers of a tennis ball met at Wimbledon earlier this summer, we were treated to a blockbusting five set thriller.
And after a first set which lasted over an hour and had more twists and turns than the craziest movie you’ve ever seen, it was looked nailed on for more of the same.
An early break by each set the stall for some brilliant, at times brutal hitting, with Del Potro’s forehand on fire.
Nadal’s attacking intent was on full show but the Spaniard’s defence was equally impressive. He saved two set points at 5-4 but managed to stay alive and force a tiebreak.
At this point, Nadal’s movement was superior but when the ball bounced into the Argie’s zone, that wound up forehand which looks like something out of a cartoon was causing havoc once more.
The final stats showed he hit 13 forehand winners to Nadal's four. In total, the winner count was 29 to 15 in Delpo's favour.
The world no 3 found himself 6-3 ahead and soon enough, the South American fans in this cavernous stadium, the biggest tennis arena in the world , were on their feet with their hero a set to the good.
Nadal was hurting badly - mentally and physically.
With the scores at 2-1 to Del Potro, the Spaniard received a lengthy medical timeout. His knees were being strapped by the trainer. The magic spray was out too.
Nadal is such a warrior,such a fearsome competitor that he grimaced, blew out his cheeks and went back to battle.
He was clearly struggling but valiantly fought on. Delpo was two breaks up with Nadal serving to stay in the set at 5-2 but the Argentine sealed the set.
His opponent was clearly struggling. Nadal began to pack away his things and that was that.
The sadness on his — and Del Potro’s face — said it all.
Nadal concluded: "He’s been through a few issues like me , but I am happy for him that’s he’s back to his top level. Injuries are part of the game — but I will not complain.
"I will keep going."